The conventional umbrella frame comprises mainly a shaft, a runner fitted slidably over the shaft, and a plurality of stretchers fastened respectively at one end thereof with the runner. The stretchers are fastened respectively at another end thereof with ribs which are arranged radially and are fastened respectively at one end thereof with the top end of the shaft for stretching the umbrella shade.
The shaft is provided in the upper segment thereof with a spring piece listened movably therewith for folding and unfolding the umbrella. When the umbrella is unfolded by sliding the runner upwards along the shaft, the spring piece is snapped into the hollow interior of the shaft by the runner so as to allow the runner to be moved further upwards to locate at a position immediately over the spring piece. As soon as the runner is moved pass the spring piece, the spring piece is snapped back to its original position to prevent the runner from moving downwards along the shaft. Before the unfolded umbrella is folded, the spring piece is forced with finger into hollow interior of the shaft to allow the runner to slide downwards along the shaft to complete the folding of the umbrella.
Such a conventional umbrella frame shaft assembly as described above is defective in design in that the fingers of a user of the umbrella are rather vulnerable to cut or bruise by the spring piece and the runner in the course of unfolding or folding the umbrella.